import java.net.URL;
import java.net.HttpURLConnection;
import java.io.InputStreamReader;
import java.io.BufferedReader;

/**
 * This program inputs a URL from the user and outputs the
 * HTTP response received by sending a GET request to the
 * specified Web server.
 */

public class WebBrowserA {

    public static void main(String args[]) {
        try {

            // Connect to the server specified by the user
            System.out.print("Please enter a URL: ");
            BufferedReader userIn = 
                new BufferedReader(new InputStreamReader(System.in));
            String url = userIn.readLine();
            HttpURLConnection connection = 
                (HttpURLConnection)(new URL(url).openConnection());

            // Send the HTTP request to the server and receive back
            // the response
            connection.connect();

            // Output the HTTP response:
            System.out.println("Server response: ");

            // 1. The status line (this may not work on all systems;
            // if not, use getResponseCode() and getResponseMethod()
            // instead)
            System.out.println(connection.getHeaderField(0));

            // 2. The header fields
            String key;
            for (int i=1; (key=connection.getHeaderFieldKey(i))!=null; i++) {
                System.out.println(key + ": " +
                                   connection.getHeaderField(i));
            }

            // 3. A blank line
            System.out.println();

            // 4. The body of the response
            BufferedReader serverIn = null;
            try {
                serverIn = new BufferedReader(
                   new InputStreamReader(connection.getInputStream()));
            }
            // Must use error stream if 404 returned
            catch (java.io.FileNotFoundException fnf) {
                serverIn = new BufferedReader(
                   new InputStreamReader(connection.getErrorStream()));
            }
            String aLine;
            while ((aLine = serverIn.readLine()) != null) {
                System.out.println(aLine);
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return;
    }
}